钢-PVA混杂纤维高性能混凝土隧道衬砌管片抗弯性能试验

Flexural Behavior Test of Steel-PVA Hybrid Fiber High Performance Concrete Tunnel Lining Segments

为研究钢纤维、聚乙烯醇(PVA)纤维、矿粉3种因素对混杂纤维高性能混凝土隧道衬砌管片受力性能的影响,针对不同体积分数的钢纤维(0.5%,1.0%,1.5%)、PVA纤维(0.1%,0.2%,0.3%)和不同掺量的矿粉(10%,20%,30%)设计了L_(9)(3^(3))的正交试验,并制作1块钢筋混凝土(RC)衬砌管片和9块钢-PVA混杂纤维高性能混凝土衬砌管片进行抗弯性能试验。研究结果表明:与RC衬砌管片相比,钢-PVA混杂纤维能显著提升衬砌管片开裂弯矩、裂缝宽度0.2 mm对应的弯矩、屈服弯矩、极限弯矩和控制裂缝开展的能力,其中钢纤维对管片极限弯矩提升最为显著,最大提升幅度达64.0%,其次是矿粉和PVA纤维;3种因素的最佳掺量组合为:1.5%钢纤维,0.3%PVA纤维和20%矿粉。对钢-PVA混杂纤维混凝土的选用原则和在衬砌管片的应用提供理论及试验依据。

In order to study the effects of steel fiber,polyvinyl alcohol(PVA)fiber and mineral powder on the force performance of hybrid fiber high performance concrete tunnel lining segments,with different volume fractions of steel fiber(0.5%,1.0%,1.5%),PVA fiber(0.1%,0.2%,0.3%)and different blending amounts of mineral powder(10%,20%,30%),L_(9)(3^(3))orthogonal test was designed,and one piece of reinforced concrete(RC)lining segment and nine pieces of steel-PVA hybrid fiber high performance concrete lining segments were made to test the flexural performance.The results show that compared with RC lining segment,steel-PVA hybrid fibers could significantly improve the cracking bending moment of lining segments,the bending moment corresponding to the crack width of 0.2 mm,the yield bending moment,the ultimate bending moment and the control ability of crack development of the lining segments,among them,the steel fiber has the most significant improvement on the ultimate bending moment of the lining segments,with the maximum improvement up to 64.0%,followed by mineral powder and PVA fiber.The optimal combination of the three factors was determined as 1.5%steel fiber,0.3%PVA fiber and 20%mineral powder.To provide theoretical and experimental basis for the selection principle of steel-PVA hybrid fiber concrete and its application in lining segments.